A synthesis has been attempted to explain the metabolic action of oestrogen-progestogens: and their action on carbohydrates, triglycerides, cholesterol, lipoproteins and coagulation has been reviewed. Carbohydrate tolerance can evolve in different ways, depending on the case. On the one hand hyperglycaemia, which is provoked by taking carbohydrates by mouth in a primitively pathological way, can be improved while on the other hand there can be diminution in carbohydrate tolerance in other cases. Two factors, however, remain constant, hyperinsulinism and resistance to insulin. There is no way of predicting how carbohydrate tolerance will behave. That is why pills that contain oestrogens and progestogens, even if they are "mini-dose" pills, are contra-indicated for women who have pancreatic diabetes. Pills with a high oestrogen content raise the triglycerides, while those which have a higher progestogen content tend to raise the blood cholesterol levels. High-density lipoprotein tends to be raised with an oestrogenic milieu and lowered with progestogens or with pills that have a strong progestogen content.